Selective tbansfer switch



SELECTIVE TRANSFER SWITCH Original Filed Junev 3. 1821 1/ l a l r 25 ak p48 F 3 '24 F0 9 -o 5 I WITNESSES INVENTOSRS 4 $Z,,'ZM'." nmf:.f Wm

'Reia ued July .13, 1926.

UNITED STATES PATENT- OFFICE.

CHARLES MOL- K058, Q1 PITTSBURGH, AND FRANK M. BILLHIHEB, OF WILKINBBURG, PENNSYLVANIA, ASSIGNOBS TO WESTINGHOUSE ELECTRIC AND MANUFACTUR- ING COMPANY, A CORTOBATION OF PENNSYLVANIA.

snnnc'rrvn TRANSFER swrrcn.

Original Re. 1,528,071,1ated larch 8, 1925, Serial No. 474,790,111 June 3, 1881. Application for reinue fled June 1, 1925. Serialwlo. 88,871.

Our invention relates to selective transfer systems and particularly to such systems as are automatic in" their operation, 7

One object of our invention is to provide 6 a transfer system for a plurality of sources of energy that shall maintain an electric circuit energized continuously.

' Another object of our'invention is to rovide a system of the above-indicated c aracter embodying means whereby one of the sources of energy may be connected to the circuit in a redetermined sequence of selection depen ing upon the condition of the sources preceding in the predetermined sequence. Another object-of our invention is to provide a system of the above-indicated character that shall be simple and inexpensive in construction and reliable in its operation.

In operating railway signals and semaphores, it is essential that the control bus from which the operating energy is derived shall always-be .energized. To obtain the continuous energization of, such a bus, it is 25 necessary to provide more than one source of electrical energy in order that the control bus may be transferred from one source of ener whenthat source'be'comes faulty, to

.anot or source of energy that is normal.

' It is also desirable that the various sources of energy be connected to the bus in a redetermined sequence. Thus, if the first of a plurality ofsources becomes faulty and inoperative, the connections should be automatically transferred to connect the bus to the second source.

Similarly, if the second source should be come faulty while the .first source remains faulty, the bus circuit should be transferred to a third source of energy. If. after the third source has been supplying energy to the bus, either the first or the second source should become normal. it is desirable that I The relay associated with the first source is connected directly thereacross, and, when energized, is adapted to effect the closing of the; first interrupter to connect the first source of energy to the bus.

The-energizing circuit of the second relay,

that controls the actuation .of the corresponding interrupter to connect the second source of electromotive force to the bus circuit, is completed through a plurality of contact members controlled by the relay associated with, and controlled by, the first source. These contacts are open while the relay associated with the first source is-energized, and are closed when that relay is deenergized. Thus, the second relay cannot be energized while the first relay is energized and is in an 0 rative position, but

may become energize upon the deenergizationof the relay associated with the first source.

Similarly, the energized circuit of the relay associated with the third source is completed through two sets of contact memtions, the fourth source of. energy is adapted.

to beconnected to the control circuit, through three sets of contact members that are severally controlled by the circuit interrupters. I

drawmg isa dia rammatic view of an electrical system em od ing our invention.

Referring to the iagram, in which all of the operating devices are shown in their. deenergized position, a plurality of sources of electromotwe force 1. 2, 3 and 4, respectively, are employed to supply energy to a control circuit 5 in a predetermined sequence of selection. The selective connection of the sources of "electromotive force may be ef- The single figure of the accompanying fected manually by means of four singlepole, double-throw switches 6, 7, 8 an 9 or may be controlled automatically by means of a plurality of circuit interrupters 10, 11. and 12. The actuation of thejmterrupters connected across t e corresponding sources of energ under predetermined conditions.

In. or er that ru ged relays and interrupter-s may be emp oye'd for efiective service, a sensitive voltage relay 16 isemployed to control the relays 13, 14 and 15 in ac-' cordance with the condition'of the corresponding sources of energy and to obviate. t e

necessity of different settings for the 'va rious relays. That is, the relays 13, 14 and 15 are age, w ereas the voltage rela 16 serves to control those relays in accor ance with the conditions of the-various sources of energy. When it is desired to operate the system manually, a four-pole, single-throw switch.

17 is employed to disconnect the automatic relays and interrupters from the several sources of ener and the switches 6, 7, 8 and 9 are close on the left side depending "upon which source of energy is to be connected to the control circuit 5.

When the first circuit is to be connected to i the bus circuit 5, only the switch 6 is closed in its left-hand position and the other switches 7, 8 and 9 are closed in their righthand positions. It the first source should become faulty, switch 7 would thereupon be closed in its left-hand position and switches 8 and 9 would be left in their previous positions. Similarly, switches 8 and 9 would-be closed in their left-hand positions when the connection of either of the other sources 3 or 4 to the. control circuit 5 should be desired.

When it is desired'to operate the s stem automatically, the switch. 17 is close and the single-pole switches 6, 7, 8 and 9 are closed in their right-hand positions. Assum' thatall the sources 1, 2, 3 and 4 are. norma the operating coil 18 of the relay 13 becomes energized and that relay closes two switches 19 and. 20 and" opens two sets ofcontact members 21 and 22, respectively.

The switch 19,'when closed, completes a I circuitfrom the source 1 through the operating coil of the interrupter 10, which is thereu on actuated to close switches 23 and 24 an to 0 en switches 25 and 26. The

. switch 23, w en closed, completes a circuit hand positions.

.- from the source- 1 of energy through the sin le-pole, double-throw switches 6, 7, 8'

an 9 to the. control circuit 5,-since the latter switches will all be closed in their right- The switch 20, when closed, completes a circuit from the source 1 through a set of rl'nitted to operate at a definite voltcontact members 27 controlled by the relay winding 18 is' short-circuited through the switch 24 of the interrupter 10 and 1s rendered ineffective for mamtainin the relay 13 in its energized position. he resistor 33 is provided to prevent a short-circuit on the source 1.

Upon the deenergization of the operating coil 18 of the-relay 13 and the conse uent opening of the switches 19 and 20 an the reengagement of the contact members 21 and 22, the voltage relay 16 is disconnected from the source 1 and. circuit is completed by the contact members-22 tor energizing the operating coil 34 of the relay 14. The

relay 14, when actuated, closes its two switches 35 and 36 and o ens two sets of contact members 27 and?) respectively.

The switch 35, when closed, energizes the operating coil of the interrupter 11 whereupon the same is actuated to close two switches 38 and 39 and to open two switches 40 and 41,-respectively. when closed, connects the source 2 to the control circuit 5 through theswitch 25, of the interrupter 10, which closed upon the deeriergiz'ation of the holding coil of the interrupter 10.

The switch 36,-whenc closed, completes a circuit from the source 2' of energy through a set of contact members 42 of the relay 15. and the contact members 21 of. the relay 13, the relay bus conductor 29 andthe operating coil 30 of the voltage relay 16 to ground, thereupon.energizing the relay 16 in accordance with the potential of the source 2. p

It-may be assumed that the source 1 remains inoperative and that the source 2 now .alsqbecomes inoperative, or, for instance,

The switch as,

byreaspn-oflow voltage. The relay 16 effects'ftlie =reengagement of its contact members 81 a'nd32, whereupon the winding 34 of the relay 14 is short-circuit'ed by' the contact members 31 and 32 through the switch 39 of the interrupter 11 and the engaged contact members 22 of the relay 13. Therelay 14 is immediatel actuated to its de e nergized position and t e interrupter" 11 is also actuated to its deenergized, or open position.

If the sources 1 and 2 remain inoperative,

the operating coil 43 of the relay 15 becomes energized by reason of its being connected ound through 37 of the rebetween the source 3 and the contact members 221m and to en its contact members28 and 42.

The c osing of the switch 44 effects the actuation of the interrupter 12 whereupon v ries.

th'eswitches 40 and 25 of its switches-46 and 47 are closed and the switch 48 is opened. The switch 46 connects the source 3 of the control circuit 5 through the interrupters 11 and 10, respectively.

If the source 3 should become inoperative while sources land 2 are inoperative, the relay 15 would be deenergized and the inter-' rupter 12-opened, as explained above for the operation of the'relays 13 and 14. The opening of the interrupter 12 would close the switch 48 whereupon the source 4 of energy would be connected to the control circuit 5 through the switches 48, 40 and 25 in se- Upon the return to normal of any one of the first three sources of energy, the corresponding relay 13, 14 or 15 would be immediately energized to close the corresponding interrupter to reconnect the' norma source to the control circuit 5. The operation of the relay 13 will effect the opening of switches 21 and 22 to preclude the energization of the relays 14 and 15 so long as such switches remained open. Similarly, the operation of the relay 14 would preclude the energization of the relay 15 by reason of the opening of switch 37.

It will thus be observed that the connection of any one of the sources of energy to the control circuit 5 is so selectively efi'ected, in a predetermined sequence, that the first normal source in the predetermined sequence will be connected to the. control circuit, irrespective of the condition. of the other sources of energy.

Our invention is not limited to the specific arrangement of the apparatus employed norto the specific types of apparatus illustrated, since various modifications may be made in the arrangement thereof within the spirit and scope of the invention, as set forth in the appended claims.

7e claim as our invention:

1. The combination with an electrical circuit and three or more sources of energy for energizing the circuit. of selective means for connecting the sources ofenergy to the circuit in a predetermined sequenccin response to predetermined conditions, for preclud ng energization of thecircuit by more than one of the sources simultaneously, and for automatically reconnecting a source of energy previously disconnected in said sequence to the circuit in response to predetermined conditions.

2. The combination with an electrical ciredit. and. N sources of energy for energizing sequence and connecting an earlier source in mined sequence is cleared of the fault. and

the circuit, of means for connecting a'pre- "determined source to the circuit and then connecting the other sources to'the circuit in a predetermined sequence only when the preceding sources in the sequence become inoperative, for precluding energization of the circuit by more than one of the sources simultaneously,-and for automatically disconnecting the last source connected in said the sequence to the circuit in response to' predetermined conditions.

3. The COlIlblnfltiOILWlth an electrical circuit and N sources of energy for energizing the circuit, of means for connecting one of the sources to the circuit only when the preceding sources, in a predetermined se quence, are'faulty, maintainingthat connection until a'prcceding source in the pred'eteu then connecting said preceding source to the circuit, thereby also simultaneously disconnecting the former source.

4. The combination with an-electrical circuit and N sources of energy for energizing the circuit, of means-for connecting one ct the sources to the circuit, in accordance with a predetermined sequence of selection, when the previous sources in the sequence become inoperative, for precluding energization of the circuit by more than one of the sources simultaneously, and for automatically disconnecting the last source connected in said sequence and connecting an earlier source in the sequence to the circuit in response to predetermined conditions.

5. The combination with an electrical. circuit and N sources of energy for energizing the circuit, of N1 relays for controlling the selective connection of one of the sources to the circuit when the previous sources. in a predetermined sequence, are inoperative, and means whereby each relay, when effective, renders theother relays in subsequent sequence thereto inefi'ective.

6. The combination with an electrical circuit and N sources of energy-for energizing the circuit, of means for automatically connecting the circuit to the first one of the sev-- eral sources that is normal, in a predeter- 11L" mined-sequence of selection, and for precluding the connection of'the circuit to any source subsequent in the sequence whfile said normal source is normal.

7. The combination with an electrical cir-' cuit and 'N sources of energy for energizing the circuit; of means for automatically connecting the circuit to one ofthe several sources, in a predetermined sequence of se lection. when the precedin sources are in- 12;; operative, and for automatically and selectively disconnecting the circuit from said source to connect the same to a preceding source, in the predetermined sequence, that has meanwhile been; rendered "operative.

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8. The combination with an electrical circuit and N sources of energy for energizing the circuit, of a plurality of'relays severally associated with each source of energy and adapted to beactuated in accordance with the condition thereof. means controlled by the relays for connecting each source to the circuit, and means controlled by the relays of one source for efi'ecting the actuation of the corresponding connecting means and for rendering predetermined relays associated with the other sources inefliective.

9. The combination with an electrical circuit and a plurality of sources of energy for energizing the circuit, of a relay for each source of energy, connecting means for each source and the circuit controlled by the corresponding relay, and means controlled by each relay for rendering other relays inefi'ective under predetermined conditions.

10. The combination with an electrical circuit and a plurality of sources of energy for energizing the circuit, and' adapted to be connected thereto in a predetermined sequence, of a relay for each source reponsive to the condition thereof for effecting the connection of the source to the circuit only when the preceding sources in the predetermined sequence are inoperative, and means whereby the connection of only one source of energy to the circuit is permitted.

11. In combination, a source of current, a second source of current, a third'source of current, a distribution system, switching means arranged to connect said sources to.

said system, andmeans operative in response to the voltage of said sources to effect the operation of saidswitching means to establish the connection of said first mentioned source to said distribution system whenever .said first source is energized. the connection of said second source to said distribution systcm whenever said first source is not energized and said second source is energized, and the connection of said third source to said distribution system whenever said third source is energized and the other two sources are not energized.

12. In combination, a source ofcurrent, a second source of current, a third source of current. a distribution system, switching means arranged to'councct said sources to said systen'i. and means operative in'respouse to the voltages of said sources to effect the operation-0f said switching means to establish the connection of said first mentioned source to said distribution system, and the disconnection of the other sources from said distribution system whenever said first source is energized, the connection of said second source to said distribution system and disconnection of the other sources from said distribution system whenever said second source is energized and said first source is not energized, and the connectionof said third source to said distribution system and the disconnection of the other sources from said distribution system whenever said third said second source to said distribution system when said first source is not energized and said second source is energized, the disconnection of said second source from said distribution system when said second source fails or said first source is energized, and

the connection of said third source to said distribution system when said second source fails, said first source is not energized and Said third source is energized.

' 14. In combination, a source of current a second source of current, a third source 0 current, a distribution system, switching means arranged to connect said sources to said system, and means 0 erative in response to the voltage of sai sources to effect the operation of said switching means to establish the connection of said first mentioned .source to said distribution system when said first source is energized, the disconnection of said first source from said distribution system when said source fails,

the connection of said second source to said distribution system when said first source is not energized and said second source is energized, the disconnection of -said second source from said distribution system when said second source fails orsaid first source is energized, the connection of said third source to said distribution system when said second source fails said first source is not energized and said third source is energized and the disconnection of said third source from said distribution system when either one of said other sources is energized.

15'. In combination, a source of current, a second source of current, a third source of current, a distribution system, switching means arranged to connect said sources to said system. and means operative in response tothe voltages of said sources to effect the operation of said switching means to establish the connection of said first mentloned source to said distribution system when said first source is energized, the disconnection of said first source from said distribution system when said source fails,

the connection of said second source to said distribution system when said first source is not energized and said second source is energized, the disconnection of said second source from said distribution system when said second source fails or said first source is energized, and the connection of said third source to said distribution system sponse to the voltages of-said sources to effect the 0 eration of said switching means to establish the connection of said first mentioned source to said distribution system when said first source is energized, the disconnection of said first source from said distribution system when said source fails, the connection of said second source to said (115* tribution system when said first source is not energized and said second source is en-' ergized, the disconnection ofsaid second source from said distribution system when 'said second source fails or said first source is energized, the connection of said third source to said distribution system when said first source fails said second source is not energized and said third source is energized;

and the disconnection of said third source from said distribution system when either one of said other sources is energized.

17. In combination, a source of current, a second source of current, a third source of current, a distribution system, switching means arranged to connect said sources to said system and means arranged to effect the operation of said switchin means to establish the connection of said first-mentioned source to said distribution system whenever said first source is'eiiergized, the connection of said second source to said distribution system whenever said first source not energized and said second source is energized, and the connection of said third source to said distribution system whenever said third source is energized and the other two sources are not energized, said last mentioned means comprising means responsive to the respective voltages of said sources, and means for automatically controllin the sequence of operation of said switc ing means. a V

18. In combination, a source of current, a second source of current, a third source of current, a distribution system, switching .ineans arranged to connect said sources to said system, and means arranged to efiect the operation of saidswitchin means to establish the connection of sai first mentioned source to said distribution system when said first source is energized,-tlie disconnection of said firstsource from said distribution system when said source 'fflllS,

the connection ofisaid second source to said distribution system when said first source is not energized and said second source is energized the disconnection of said second source iroin said distribution system when said second source fails or said first source is energized, the connection of said third source 'to said distribution system when said first source fails said second source is not energized and said'third source is energized and the disconnectionof said third sourcefrom said distribution system when eitherone of said other sources is energized or said third source jails, said last mentioned means comprising means responsive to the voltages of i said sources, and means for automatically controlling the sequence of operation of said switching means:

1 19. Anelectric system comprising a source of current, a second source of current, a I

third source of current, a distribution system,- switching means arranged to connect each source to said distribution system, and means arranged to 'eifect the connection of said first mentioned source to said distribu- LiOll system whenever said first mentioned source is energized, the connection of said second source to said distribution system whenever said first source is not energized and said second source is energized and the connection of said third source to said distribution system whenever said third source is energized and the other two sources are not energized, said last mentioned means comprising means responsive to the respective voltages of said sources, and circuit controlling ineans arranged ill cooperative-relationship with each of said switching means and arranged to cooperate with said voltage responsive means to control said switching means.

20. An electric system comprising a source of current, a second source of current, ,a third source of current, a distribution system, switching niea'ns arranged to connect each source to said distribution system, means arranged to effect the connection of Said first mentioned source to said distribution system when said first source is energized, the disconnection of said first source from said distribution system when said source fails, the connection of said second source to said distribution system when said first source is not energized and said second source is energized, the disconiiection of said second source from said distribution system when said second source fails or said first source is energized, the connection of said .third source to said distribution system when said first source fails said second source is not energized and said third source is energized, and the disconnection of I said third source from said distribution system when either one of said other sources is energized, said last mentioned means comprising means responsive to the respective "oltages of said sources, and circuit controlling means arranged in cooperative relationship with each of sai'd'switching means and arranged to cooperate with said voltage responsive means to control said switching means. 21. The combination with a plurality of sources of energy-tosup ly energy to a pluor controlrality of bus sections, 0 means ling the connection of said sources to-the bus 1 sections in a predetermined sequence to permit the respective sources to supply energy to the associated bus sections and means for substituting one/of the sources for one of the previously-connected sources, upon the occurrence 0t abnormal conditions in-said previously connected source, to permit the substituted source of energy to supply energy to the bus section associated with the faulty source of energy.

In testimony whereof, we have hereunto subscribed our namesthis 29th day of May, I

CHARLES McL. MOSS. FRANK M. BILLHIMER. 

